F AMILIES OF E LEMENTS By Mary Katherine Paulone

S ODIUM Alkali Metals Group 1 Na Atomic Number 11 Soft, silvery-white, highly reactive Found in table salt One valence electron Essential element for all animals and some plants

C ALCIUM Alkaline-Earth Metal Group 2 Ca Atomic Number 20 Soft gray Less reactive than Alkali Metals Two valence electrons Fifth most abundant element by mass in Earth’s crust Used for many cellular processes Found in bones, teeth, and shells of animals

M ERCURY Transition Metal Group 12 Hg Atomic Number 80 Quicksilver Much less reactive then Groups one and two Lose electrons to form positive ions Only liquid metal under standard temperatures and pressures Used in thermometers

A LUMINUM Boron Family 3 Valence Electrons Al Atomic Number 13 Silvery, white, soft Group 13 Most abundant metal in Earth’s crust Found in cans, foil, siding

T IN Carbon Family 4 Valence Electrons Sn Atomic Number 50 Silvery or Gray Group 14 Used to coat steel in making rust proof cans

P HOSPHORUS Nitrogen Family 5 Valence Electrons P Atomic Number 15 Solid Form Yellow or red form Group 15 Basic part of organs and bones

S ULFUR Oxygen Family 6 Valence Electrons S Atomic Number 16 Yellow solid Group 16 Used to make matches and rubber tires

F LUORINE Halogen Family 7 Valence Electrons F Atomic Number 9 Pale yellow gas at standard temperature and pressure Group 17 Lightest Halogen Compounds used in toothpaste, insecticides, and in the preparation of some plastics

N EON Noble Gas 8 Valence Electrons Ne Atomic Number 10 Colorless and odorless Group 18 Gas Not react with other elements “Happy” Compressed in glow lamps

L ANTHANIDES Family begins with element lanthanum Atomic numbers Used in production of steel and glass Rare Earth elements Electron configurations determined by experiments

A CTINIDES Family begins with actinium Atomic Numbers Radioactive Give off high energy particles Used in nuclear weapon tests

H YDROGEN Atomic Number 1 H Lightest element Colorless gas Non-toxic and highly combustible Most abundant chemical substance Has one proton and on electron No neutrons